udp over tcp

shadowsocks/common.py

@@ -144,6 +144,8 @@ def parse_header(data):
     dest_addr = None
     dest_port = None
     header_length = 0
+    connecttype = (addrtype & 8) and 1 or 0
+    addrtype &= ~8
     if addrtype == ADDRTYPE_IPV4:
         if len(data) >= 7:
             dest_addr = socket.inet_ntoa(data[1:5])
@@ -171,11 +173,11 @@ def parse_header(data):
         else:
             logging.warn('header is too short')
     else:
-        logging.warn('unsupported addrtype %d, maybe wrong password or '
-                     'encryption method' % addrtype)
+        logging.warn('unsupported addrtype %d, maybe wrong password' %
+                     addrtype)
     if dest_addr is None:
         return None
-    return addrtype, to_bytes(dest_addr), dest_port, header_length
+    return connecttype, to_bytes(dest_addr), dest_port, header_length
 
 
 class IPNetwork(object):

shadowsocks/crypto/ctypes_libsodium.py

@@ -0,0 +1,135 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2014 clowwindy
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from __future__ import absolute_import, division, print_function, \
+    with_statement
+
+import logging
+from ctypes import CDLL, c_char_p, c_int, c_ulonglong, byref, \
+    create_string_buffer, c_void_p
+
+__all__ = ['ciphers']
+
+libsodium = None
+loaded = False
+
+buf_size = 2048
+
+# for salsa20 and chacha20
+BLOCK_SIZE = 64
+
+
+def load_libsodium():
+    global loaded, libsodium, buf
+
+    from ctypes.util import find_library
+    for p in ('sodium',):
+        libsodium_path = find_library(p)
+        if libsodium_path:
+            break
+    else:
+        raise Exception('libsodium not found')
+    logging.info('loading libsodium from %s', libsodium_path)
+    libsodium = CDLL(libsodium_path)
+    libsodium.sodium_init.restype = c_int
+    libsodium.crypto_stream_salsa20_xor_ic.restype = c_int
+    libsodium.crypto_stream_salsa20_xor_ic.argtypes = (c_void_p, c_char_p,
+                                                       c_ulonglong,
+                                                       c_char_p, c_ulonglong,
+                                                       c_char_p)
+    libsodium.crypto_stream_chacha20_xor_ic.restype = c_int
+    libsodium.crypto_stream_chacha20_xor_ic.argtypes = (c_void_p, c_char_p,
+                                                        c_ulonglong,
+                                                        c_char_p, c_ulonglong,
+                                                        c_char_p)
+
+    libsodium.sodium_init()
+
+    buf = create_string_buffer(buf_size)
+    loaded = True
+
+
+class Salsa20Crypto(object):
+    def __init__(self, cipher_name, key, iv, op):
+        if not loaded:
+            load_libsodium()
+        self.key = key
+        self.iv = iv
+        self.key_ptr = c_char_p(key)
+        self.iv_ptr = c_char_p(iv)
+        if cipher_name == b'salsa20':
+            self.cipher = libsodium.crypto_stream_salsa20_xor_ic
+        elif cipher_name == b'chacha20':
+            self.cipher = libsodium.crypto_stream_chacha20_xor_ic
+        else:
+            raise Exception('Unknown cipher')
+        # byte counter, not block counter
+        self.counter = 0
+
+    def update(self, data):
+        global buf_size, buf
+        l = len(data)
+
+        # we can only prepend some padding to make the encryption align to
+        # blocks
+        padding = self.counter % BLOCK_SIZE
+        if buf_size < padding + l:
+            buf_size = (padding + l) * 2
+            buf = create_string_buffer(buf_size)
+
+        if padding:
+            data = (b'\0' * padding) + data
+        self.cipher(byref(buf), c_char_p(data), padding + l,
+                    self.iv_ptr, int(self.counter / BLOCK_SIZE), self.key_ptr)
+        self.counter += l
+        # buf is copied to a str object when we access buf.raw
+        # strip off the padding
+        return buf.raw[padding:padding + l]
+
+
+ciphers = {
+    b'salsa20': (32, 8, Salsa20Crypto),
+    b'chacha20': (32, 8, Salsa20Crypto),
+}
+
+
+def test_salsa20():
+    from shadowsocks.crypto import util
+
+    cipher = Salsa20Crypto(b'salsa20', b'k' * 32, b'i' * 16, 1)
+    decipher = Salsa20Crypto(b'salsa20', b'k' * 32, b'i' * 16, 0)
+
+    util.run_cipher(cipher, decipher)
+
+
+def test_chacha20():
+    from shadowsocks.crypto import util
+
+    cipher = Salsa20Crypto(b'chacha20', b'k' * 32, b'i' * 16, 1)
+    decipher = Salsa20Crypto(b'chacha20', b'k' * 32, b'i' * 16, 0)
+
+    util.run_cipher(cipher, decipher)
+
+
+if __name__ == '__main__':
+    test_chacha20()
+    test_salsa20()

shadowsocks/crypto/ctypes_openssl.py

@@ -0,0 +1,188 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2014 clowwindy
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from __future__ import absolute_import, division, print_function, \
+    with_statement
+
+import logging
+from ctypes import CDLL, c_char_p, c_int, c_long, byref,\
+    create_string_buffer, c_void_p
+
+__all__ = ['ciphers']
+
+libcrypto = None
+loaded = False
+
+buf_size = 2048
+
+
+def load_openssl():
+    global loaded, libcrypto, buf
+
+    from ctypes.util import find_library
+    for p in ('crypto', 'eay32', 'libeay32'):
+        libcrypto_path = find_library(p)
+        if libcrypto_path:
+            break
+    else:
+        raise Exception('libcrypto(OpenSSL) not found')
+    logging.info('loading libcrypto from %s', libcrypto_path)
+    libcrypto = CDLL(libcrypto_path)
+    libcrypto.EVP_get_cipherbyname.restype = c_void_p
+    libcrypto.EVP_CIPHER_CTX_new.restype = c_void_p
+
+    libcrypto.EVP_CipherInit_ex.argtypes = (c_void_p, c_void_p, c_char_p,
+                                            c_char_p, c_char_p, c_int)
+
+    libcrypto.EVP_CipherUpdate.argtypes = (c_void_p, c_void_p, c_void_p,
+                                           c_char_p, c_int)
+
+    libcrypto.EVP_CIPHER_CTX_cleanup.argtypes = (c_void_p,)
+    libcrypto.EVP_CIPHER_CTX_free.argtypes = (c_void_p,)
+    if hasattr(libcrypto, 'OpenSSL_add_all_ciphers'):
+        libcrypto.OpenSSL_add_all_ciphers()
+
+    buf = create_string_buffer(buf_size)
+    loaded = True
+
+
+def load_cipher(cipher_name):
+    func_name = b'EVP_' + cipher_name.replace(b'-', b'_')
+    if bytes != str:
+        func_name = str(func_name, 'utf-8')
+    cipher = getattr(libcrypto, func_name, None)
+    if cipher:
+        cipher.restype = c_void_p
+        return cipher()
+    return None
+
+
+class CtypesCrypto(object):
+    def __init__(self, cipher_name, key, iv, op):
+        if not loaded:
+            load_openssl()
+        self._ctx = None
+        cipher = libcrypto.EVP_get_cipherbyname(cipher_name)
+        if not cipher:
+            cipher = load_cipher(cipher_name)
+        if not cipher:
+            raise Exception('cipher %s not found in libcrypto' % cipher_name)
+        key_ptr = c_char_p(key)
+        iv_ptr = c_char_p(iv)
+        self._ctx = libcrypto.EVP_CIPHER_CTX_new()
+        if not self._ctx:
+            raise Exception('can not create cipher context')
+        r = libcrypto.EVP_CipherInit_ex(self._ctx, cipher, None,
+                                        key_ptr, iv_ptr, c_int(op))
+        if not r:
+            self.clean()
+            raise Exception('can not initialize cipher context')
+
+    def update(self, data):
+        global buf_size, buf
+        cipher_out_len = c_long(0)
+        l = len(data)
+        if buf_size < l:
+            buf_size = l * 2
+            buf = create_string_buffer(buf_size)
+        libcrypto.EVP_CipherUpdate(self._ctx, byref(buf),
+                                   byref(cipher_out_len), c_char_p(data), l)
+        # buf is copied to a str object when we access buf.raw
+        return buf.raw[:cipher_out_len.value]
+
+    def __del__(self):
+        self.clean()
+
+    def clean(self):
+        if self._ctx:
+            libcrypto.EVP_CIPHER_CTX_cleanup(self._ctx)
+            libcrypto.EVP_CIPHER_CTX_free(self._ctx)
+
+
+ciphers = {
+    b'aes-128-cfb': (16, 16, CtypesCrypto),
+    b'aes-192-cfb': (24, 16, CtypesCrypto),
+    b'aes-256-cfb': (32, 16, CtypesCrypto),
+    b'aes-128-ofb': (16, 16, CtypesCrypto),
+    b'aes-192-ofb': (24, 16, CtypesCrypto),
+    b'aes-256-ofb': (32, 16, CtypesCrypto),
+    b'aes-128-ctr': (16, 16, CtypesCrypto),
+    b'aes-192-ctr': (24, 16, CtypesCrypto),
+    b'aes-256-ctr': (32, 16, CtypesCrypto),
+    b'aes-128-cfb8': (16, 16, CtypesCrypto),
+    b'aes-192-cfb8': (24, 16, CtypesCrypto),
+    b'aes-256-cfb8': (32, 16, CtypesCrypto),
+    b'aes-128-cfb1': (16, 16, CtypesCrypto),
+    b'aes-192-cfb1': (24, 16, CtypesCrypto),
+    b'aes-256-cfb1': (32, 16, CtypesCrypto),
+    b'bf-cfb': (16, 8, CtypesCrypto),
+    b'camellia-128-cfb': (16, 16, CtypesCrypto),
+    b'camellia-192-cfb': (24, 16, CtypesCrypto),
+    b'camellia-256-cfb': (32, 16, CtypesCrypto),
+    b'cast5-cfb': (16, 8, CtypesCrypto),
+    b'des-cfb': (8, 8, CtypesCrypto),
+    b'idea-cfb': (16, 8, CtypesCrypto),
+    b'rc2-cfb': (16, 8, CtypesCrypto),
+    b'rc4': (16, 0, CtypesCrypto),
+    b'seed-cfb': (16, 16, CtypesCrypto),
+}
+
+
+def run_method(method):
+    from shadowsocks.crypto import util
+
+    cipher = CtypesCrypto(method, b'k' * 32, b'i' * 16, 1)
+    decipher = CtypesCrypto(method, b'k' * 32, b'i' * 16, 0)
+
+    util.run_cipher(cipher, decipher)
+
+
+def test_aes_128_cfb():
+    run_method(b'aes-128-cfb')
+
+
+def test_aes_256_cfb():
+    run_method(b'aes-256-cfb')
+
+
+def test_aes_128_cfb8():
+    run_method(b'aes-128-cfb8')
+
+
+def test_aes_256_ofb():
+    run_method(b'aes-256-ofb')
+
+
+def test_aes_256_ctr():
+    run_method(b'aes-256-ctr')
+
+
+def test_bf_cfb():
+    run_method(b'bf-cfb')
+
+
+def test_rc4():
+    run_method(b'rc4')
+
+
+if __name__ == '__main__':
+    test_aes_128_cfb()

shadowsocks/crypto/m2.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2014 clowwindy
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from __future__ import absolute_import, division, print_function, \
+    with_statement
+
+import sys
+import logging
+
+__all__ = ['ciphers']
+
+has_m2 = True
+try:
+    __import__('M2Crypto')
+except ImportError:
+    has_m2 = False
+
+
+def create_cipher(alg, key, iv, op, key_as_bytes=0, d=None, salt=None, i=1,
+                  padding=1):
+
+    import M2Crypto.EVP
+    return M2Crypto.EVP.Cipher(alg.replace('-', '_'), key, iv, op,
+                               key_as_bytes=0, d='md5', salt=None, i=1,
+                               padding=1)
+
+
+def err(alg, key, iv, op, key_as_bytes=0, d=None, salt=None, i=1, padding=1):
+    logging.error(('M2Crypto is required to use %s, please run'
+                   ' `apt-get install python-m2crypto`') % alg)
+    sys.exit(1)
+
+
+if has_m2:
+    ciphers = {
+        b'aes-128-cfb': (16, 16, create_cipher),
+        b'aes-192-cfb': (24, 16, create_cipher),
+        b'aes-256-cfb': (32, 16, create_cipher),
+        b'bf-cfb': (16, 8, create_cipher),
+        b'camellia-128-cfb': (16, 16, create_cipher),
+        b'camellia-192-cfb': (24, 16, create_cipher),
+        b'camellia-256-cfb': (32, 16, create_cipher),
+        b'cast5-cfb': (16, 8, create_cipher),
+        b'des-cfb': (8, 8, create_cipher),
+        b'idea-cfb': (16, 8, create_cipher),
+        b'rc2-cfb': (16, 8, create_cipher),
+        b'rc4': (16, 0, create_cipher),
+        b'seed-cfb': (16, 16, create_cipher),
+    }
+else:
+    ciphers = {}
+
+
+def run_method(method):
+    from shadowsocks.crypto import util
+
+    cipher = create_cipher(method, b'k' * 32, b'i' * 16, 1)
+    decipher = create_cipher(method, b'k' * 32, b'i' * 16, 0)
+
+    util.run_cipher(cipher, decipher)
+
+
+def check_env():
+    # skip this test on pypy and Python 3
+    try:
+        import __pypy__
+        del __pypy__
+        from nose.plugins.skip import SkipTest
+        raise SkipTest
+    except ImportError:
+        pass
+    if bytes != str:
+        from nose.plugins.skip import SkipTest
+        raise SkipTest
+
+
+def test_aes_128_cfb():
+    check_env()
+    run_method(b'aes-128-cfb')
+
+
+def test_aes_256_cfb():
+    check_env()
+    run_method(b'aes-256-cfb')
+
+
+def test_bf_cfb():
+    check_env()
+    run_method(b'bf-cfb')
+
+
+def test_rc4():
+    check_env()
+    run_method(b'rc4')
+
+
+if __name__ == '__main__':
+    test_aes_128_cfb()

shadowsocks/encrypt.py

@@ -47,6 +47,8 @@ def try_cipher(key, method=None):
 def EVP_BytesToKey(password, key_len, iv_len):
     # equivalent to OpenSSL's EVP_BytesToKey() with count 1
     # so that we make the same key and iv as nodejs version
+    if hasattr(password, 'encode'):
+        password = password.encode('utf-8')
     cached_key = '%s-%d-%d' % (password, key_len, iv_len)
     r = cached_keys.get(cached_key, None)
     if r:

shadowsocks/tcprelay.py

@@ -101,6 +101,7 @@ class TCPRelayHandler(object):
         self._loop = loop
         self._local_sock = local_sock
         self._remote_sock = None
+        self._remote_udp = False
         self._config = config
         self._dns_resolver = dns_resolver
 
@@ -190,6 +191,27 @@ class TCPRelayHandler(object):
         # and update the stream to wait for writing
         if not data or not sock:
             return False
+        #logging.debug("_write_to_sock %s %s %s" % (self._remote_sock, sock, self._remote_udp))
+        if self._remote_sock == sock and self._remote_udp:
+            try:
+                #TODO
+                data = data[3:]
+                header_result = parse_header(data)
+                if header_result is None:
+                    return False
+                connecttype, dest_addr, dest_port, header_length = header_result
+                addrs = socket.getaddrinfo(dest_addr, dest_port, 0,
+                        socket.SOCK_DGRAM, socket.SOL_UDP)
+                if addrs:
+                    af, socktype, proto, canonname, server_addr = addrs[0]
+                    data = data[header_length:]
+                    sock.sendto(data, server_addr)
+
+            except Exception as e:
+                trace = traceback.format_exc()
+                logging.error(trace)
+            return True
+
         uncomplete = False
         try:
             l = len(data)
@@ -203,6 +225,7 @@ class TCPRelayHandler(object):
                             errno.EWOULDBLOCK):
                 uncomplete = True
             else:
+                #traceback.print_exc()
                 shell.print_exception(e)
                 self.destroy()
                 return False
@@ -291,11 +314,13 @@ class TCPRelayHandler(object):
             header_result = parse_header(data)
             if header_result is None:
                 raise Exception('can not parse header')
-            addrtype, remote_addr, remote_port, header_length = header_result
-            logging.info('connecting %s:%d from %s:%d' %
-                         (common.to_str(remote_addr), remote_port,
+            connecttype, remote_addr, remote_port, header_length = header_result
+            logging.info('%s connecting %s:%d from %s:%d' %
+                        ((connecttype == 0) and 'tcp' or 'udp',
+                            common.to_str(remote_addr), remote_port,
                             self._client_address[0], self._client_address[1]))
             self._remote_address = (common.to_str(remote_addr), remote_port)
+            self._remote_udp = (connecttype != 0)
             # pause reading
             self._update_stream(STREAM_UP, WAIT_STATUS_WRITING)
             self._stage = STAGE_DNS
@@ -323,8 +348,10 @@ class TCPRelayHandler(object):
             self.destroy()
 
     def _create_remote_socket(self, ip, port):
-        addrs = socket.getaddrinfo(ip, port, 0, socket.SOCK_STREAM,
-                                   socket.SOL_TCP)
+        if self._remote_udp:
+            addrs = socket.getaddrinfo(ip, port, 0, socket.SOCK_DGRAM, socket.SOL_UDP)
+        else:
+            addrs = socket.getaddrinfo(ip, port, 0, socket.SOCK_STREAM, socket.SOL_TCP)
         if len(addrs) == 0:
             raise Exception("getaddrinfo failed for %s:%d" % (ip, port))
         af, socktype, proto, canonname, sa = addrs[0]
@@ -336,6 +363,9 @@ class TCPRelayHandler(object):
         self._remote_sock = remote_sock
         self._fd_to_handlers[remote_sock.fileno()] = self
         remote_sock.setblocking(False)
+        if self._remote_udp:
+            pass
+        else:
             remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
         return remote_sock
 
@@ -368,6 +398,10 @@ class TCPRelayHandler(object):
                         # else do connect
                         remote_sock = self._create_remote_socket(remote_addr,
                                                                  remote_port)
+                        if self._remote_udp:
+                            self._loop.add(remote_sock,
+                                           eventloop.POLL_IN)
+                        else:
                             try:
                                 remote_sock.connect((remote_addr, remote_port))
                             except (OSError, IOError) as e:
@@ -407,6 +441,7 @@ class TCPRelayHandler(object):
             data = self._encryptor.decrypt(data)
             if not data:
                 return
+        self._server.server_transfer_ul += len(data)
         if self._stage == STAGE_STREAM:
             if self._is_local:
                 data = self._encryptor.encrypt(data)
@@ -428,14 +463,26 @@ class TCPRelayHandler(object):
         self._update_activity()
         data = None
         try:
+            if self._remote_udp:
+                data, addr = self._remote_sock.recvfrom(BUF_SIZE)
+                port = struct.pack('>H', addr[1])
+                try:
+                    ip = socket.inet_aton(addr[0])
+                    data = '\x00\x00\x00\x01' + ip + port + data
+                except Exception as e:
+                    ip = socket.inet_pton(socket.AF_INET6, addr[0])
+                    data = '\x00\x00\x00\x04' + ip + port + data
+                logging.info('udp recvfrom %s:%d %d bytes to %s:%d' % (addr[0], addr[1], len(data), self._client_address[0], self._client_address[1]))
+            else:
                 data = self._remote_sock.recv(BUF_SIZE)
         except (OSError, IOError) as e:
             if eventloop.errno_from_exception(e) in \
-                    (errno.ETIMEDOUT, errno.EAGAIN, errno.EWOULDBLOCK):
+                    (errno.ETIMEDOUT, errno.EAGAIN, errno.EWOULDBLOCK, 10035): #errno.WSAEWOULDBLOCK
                 return
         if not data:
             self.destroy()
             return
+        self._server.server_transfer_dl += len(data)
         if self._is_local:
             data = self._encryptor.decrypt(data)
         else:
@@ -558,6 +605,8 @@ class TCPRelay(object):
         self._eventloop = None
         self._fd_to_handlers = {}
         self._last_time = time.time()
+        self.server_transfer_ul = 0L
+        self.server_transfer_dl = 0L
 
         self._timeout = config['timeout']
         self._timeouts = []  # a list for all the handlers

shadowsocks/udprelay.py

@@ -162,7 +162,7 @@ class UDPRelay(object):
         header_result = parse_header(data)
         if header_result is None:
             return
-        addrtype, dest_addr, dest_port, header_length = header_result
+        connecttype, dest_addr, dest_port, header_length = header_result
 
         if self._is_local:
             server_addr, server_port = self._get_a_server()
@@ -173,6 +173,7 @@ class UDPRelay(object):
         client = self._cache.get(key, None)
         if not client:
             # TODO async getaddrinfo
+            logging.info('UDP handle_server %s:%d from %s:%d' % (common.to_str(server_addr), server_port, self._listen_addr, self._listen_port))
             addrs = socket.getaddrinfo(server_addr, server_port, 0,
                                        socket.SOCK_DGRAM, socket.SOL_UDP)
             if addrs:
@@ -233,7 +234,7 @@ class UDPRelay(object):
             header_result = parse_header(data)
             if header_result is None:
                 return
-            # addrtype, dest_addr, dest_port, header_length = header_result
+            # connecttype, dest_addr, dest_port, header_length = header_result
             response = b'\x00\x00\x00' + data
         client_addr = self._client_fd_to_server_addr.get(sock.fileno())
         if client_addr: